1. Field of the Invention
The present invention relates to a golf club, and more particularly to a golf club wood head having a relatively high moment of inertia which is very forgiving to an off-center hit.
2. Description of the Prior Art
Numerous types of wood clubs are known in the art for driving golf balls a long distance. Prior to the advent and golfer acceptance of metal woods in the late 1970s to 1980s, wood golf clubs were known. These wood clubs typically were composed of a wooden head connected to the end of a shaft. The head of the wood club was solid wood, hence the term “wood” for the club. Typically, the wooden club head had a metal sole plate (a relatively thin metal plate attached to the bottom surface of the wooden head) and a central club face insert to improve the durability and wear characteristics of the club head.
It is now appreciated that these antiquated wooden club heads had a relatively low moment of inertia. The moment of inertia of a club head or other body is a measure of its susceptibility to rotation. A well-known example demonstrating the effect of a change in the moment of inertia is a spinning figure skater—the skater spins more slowly when the skater's arms are outstretched sideways (relatively high moment of inertia) as compared to when the arms are held close to the body or when extended straight up (relatively low moment of inertia).
For wood clubs, the greater the moment of inertia, the less susceptible the club head is to rotating when the club face impacts a ball with an off-center hit. Thus, a higher moment of inertia club head will produce a better shot on an off-center hit than a club head with a lower moment of inertia. With this principle in mind, numerous improvements to metal wood clubs are known and have been proposed.
For example, metal wood clubs were developed which included a metal club head having a hollow metal body. The mass of the club head was located substantially around the perimeter of the club head. For a given size club head, this resulted in a substantially greater moment of inertia than a solid wooden club head where the mass was distributed throughout the body of the club head.
Other “improved” metal club heads increased the club head size or volume while maintaining the club head weight essentially the same (typically about 200 grams or about 7 ounces) while overall generally having the typical wood head shape.
A need exists for an improved wood golf club which has a relatively high moment of inertia around the center of gravity of the club head, and thus results in improved directional stability and flight distance of a hit ball without requiring as large a club head volume for a given moment of inertia compared to a metal wood club head having an overall generally typical or conventional wood head shape, such as the stated conventional club head shape in FIG. 1 of U.S. Pat. No. 5,645,495, for example.